CVE-2015-1353 in PHP
Summary
by MITRE
Multiple integer overflows in the calendar extension in PHP through 5.6.7 allow remote attackers to cause a denial of service or possibly have unspecified other impact via a crafted year value to (1) the GregorianToSdn function in gregor.c or (2) the JulianToSdn function in julian.c, as demonstrated by a crafted third argument to the gregoriantojd or juliantojd function.
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Analysis
by VulDB Data Team • 03/04/2025
The vulnerability identified as CVE-2015-1353 represents a critical integer overflow issue within PHP's calendar extension, specifically affecting versions through 5.6.7. This flaw exists in the core calendar functionality that converts calendar dates to Julian day numbers, which are fundamental operations for date calculations in many applications. The vulnerability stems from inadequate input validation and overflow handling in two primary functions: GregorianToSdn in gregor.c and JulianToSdn in julian.c, which are invoked through the gregoriantojd and juliantojd functions. These functions process date conversions by accepting year values as parameters and performing mathematical calculations that can exceed the maximum representable integer values for the system architecture.
The technical exploitation of this vulnerability occurs when remote attackers supply crafted year values that trigger integer overflow conditions during the conversion process. When these overflow conditions manifest, they can cause the PHP interpreter to behave unpredictably, leading to denial of service scenarios where the application crashes or becomes unresponsive. The integer overflow vulnerability is classified under CWE-190, which specifically addresses integer overflow conditions that can result in unexpected behavior and potentially allow attackers to execute arbitrary code or cause system instability. The flaw operates at the core mathematical computation level where large year values are processed, and the resulting arithmetic operations exceed the bounds of standard integer types, causing undefined behavior in the application's memory management.
The operational impact of CVE-2015-1353 extends beyond simple denial of service to potentially enable more severe consequences depending on the application's execution environment. When exploited, this vulnerability can disrupt web applications that rely on PHP's calendar functions for date processing, particularly those handling user input through forms or API endpoints. The vulnerability's potential for unspecified other impacts suggests that in certain configurations, attackers might be able to leverage the integer overflow to execute code or gain additional privileges, making it particularly dangerous for applications running in multi-tenant environments or systems with elevated privileges. This type of vulnerability aligns with ATT&CK technique T1059.007, which involves the use of remote services to execute commands, as attackers can manipulate date inputs to trigger system-level failures.
The mitigation strategy for this vulnerability requires immediate patching of affected PHP installations to version 5.6.8 or later, where the integer overflow conditions have been addressed through proper input validation and overflow checking mechanisms. System administrators should also implement input sanitization measures at the application level to validate date inputs before they reach the calendar extension functions, particularly for any user-provided date data. Additionally, monitoring and logging should be enhanced to detect unusual date processing patterns that might indicate exploitation attempts, as this vulnerability can be used both for denial of service attacks and as a potential stepping stone for more sophisticated attacks. Organizations should also consider implementing web application firewalls that can detect and block malformed date parameters, and regular security assessments should be conducted to identify similar integer overflow vulnerabilities in other system components. The vulnerability demonstrates the importance of proper integer handling in mathematical operations and underscores the need for comprehensive security testing of mathematical libraries and date processing functions in web applications.